LXR qemu/hw/s390x/tod.c

   1/*
   2 * TOD (Time Of Day) clock
   3 *
   4 * Copyright 2018 Red Hat, Inc.
   5 * Author(s): David Hildenbrand <david@redhat.com>
   6 *
   7 * This work is licensed under the terms of the GNU GPL, version 2 or later.
   8 * See the COPYING file in the top-level directory.
   9 */
  10
  11#include "qemu/osdep.h"
  12#include "hw/s390x/tod.h"
  13#include "qapi/error.h"
  14#include "qemu/error-report.h"
  15#include "qemu/module.h"
  16#include "sysemu/kvm.h"
  17#include "sysemu/tcg.h"
  18#include "sysemu/qtest.h"
  19#include "migration/qemu-file-types.h"
  20#include "migration/register.h"
  21
  22void s390_init_tod(void)
  23{
  24    Object *obj;
  25
  26    if (kvm_enabled()) {
  27        obj = object_new(TYPE_KVM_S390_TOD);
  28    } else if (tcg_enabled()) {
  29        obj = object_new(TYPE_QEMU_S390_TOD);
  30    } else if (qtest_enabled()) {
  31        return;
  32    } else {
  33        error_report("current accelerator not handled in s390_init_tod!");
  34        abort();
  35    }
  36    object_property_add_child(qdev_get_machine(), TYPE_S390_TOD, obj);
  37    object_unref(obj);
  38
  39    qdev_realize(DEVICE(obj), NULL, &error_fatal);
  40}
  41
  42S390TODState *s390_get_todstate(void)
  43{
  44    static S390TODState *ts;
  45
  46    if (!ts) {
  47        ts = S390_TOD(object_resolve_path_type("", TYPE_S390_TOD, NULL));
  48    }
  49
  50    return ts;
  51}
  52
  53#define S390_TOD_CLOCK_VALUE_MISSING    0x00
  54#define S390_TOD_CLOCK_VALUE_PRESENT    0x01
  55
  56static void s390_tod_save(QEMUFile *f, void *opaque)
  57{
  58    S390TODState *td = opaque;
  59    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
  60    Error *err = NULL;
  61    S390TOD tod;
  62
  63    tdc->get(td, &tod, &err);
  64    if (err) {
  65        warn_report_err(err);
  66        error_printf("Guest clock will not be migrated "
  67                     "which could cause the guest to hang.");
  68        qemu_put_byte(f, S390_TOD_CLOCK_VALUE_MISSING);
  69        return;
  70    }
  71
  72    qemu_put_byte(f, S390_TOD_CLOCK_VALUE_PRESENT);
  73    qemu_put_byte(f, tod.high);
  74    qemu_put_be64(f, tod.low);
  75}
  76
  77static int s390_tod_load(QEMUFile *f, void *opaque, int version_id)
  78{
  79    S390TODState *td = opaque;
  80    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
  81    Error *err = NULL;
  82    S390TOD tod;
  83
  84    if (qemu_get_byte(f) == S390_TOD_CLOCK_VALUE_MISSING) {
  85        warn_report("Guest clock was not migrated. This could "
  86                    "cause the guest to hang.");
  87        return 0;
  88    }
  89
  90    tod.high = qemu_get_byte(f);
  91    tod.low = qemu_get_be64(f);
  92
  93    tdc->set(td, &tod, &err);
  94    if (err) {
  95        error_report_err(err);
  96        return -1;
  97    }
  98    return 0;
  99}
 100
 101static SaveVMHandlers savevm_tod = {
 102    .save_state = s390_tod_save,
 103    .load_state = s390_tod_load,
 104};
 105
 106static void s390_tod_realize(DeviceState *dev, Error **errp)
 107{
 108    S390TODState *td = S390_TOD(dev);
 109
 110    /* Legacy migration interface */
 111    register_savevm_live("todclock", 0, 1, &savevm_tod, td);
 112}
 113
 114static void s390_tod_class_init(ObjectClass *oc, void *data)
 115{
 116    DeviceClass *dc = DEVICE_CLASS(oc);
 117
 118    dc->desc = "TOD (Time Of Day) Clock";
 119    dc->realize = s390_tod_realize;
 120    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 121
 122    /* We only have one TOD clock in the system attached to the machine */
 123    dc->user_creatable = false;
 124}
 125
 126static TypeInfo s390_tod_info = {
 127    .name = TYPE_S390_TOD,
 128    .parent = TYPE_DEVICE,
 129    .instance_size = sizeof(S390TODState),
 130    .class_init = s390_tod_class_init,
 131    .class_size = sizeof(S390TODClass),
 132    .abstract = true,
 133};
 134
 135static void register_types(void)
 136{
 137    type_register_static(&s390_tod_info);
 138}
 139type_init(register_types);
 140